Characterization Of The Gut DNA Virome In Children With Autism Spectrum Disorder

Objective Autism spectrum disorder(ASD)is a group of abnormal neurodevelopmental disorders with clinical symptoms of social interaction difficulties,repetitive behaviors,and narrow interests,which can appear as early as infancy.The genetic and many non-genetic factors make the etiology of the ASD complex and the causative mechanism is unknown.Recently,many studies have identified a potential role for the gut flora in ASD,but little research has been done on how the gut virome changes in ASD.This experiment will detect and analyze the DNA virome in the stools of children with ASD by viral metagenomics methods,and then identify the changes in the intestinal DNA virome of children with ASD compared with their healthy siblings.MethodsA cross-sectional study using a case-control approach.Two-child families within Anhui Province,China were recruited to participate.Each of these families had at least two children,one with a diagnosis of ASD and the other a healthy child with the same father and mother who had lived together for a long time.Both groups of children did not use anti-infective drugs,probiotics,prebiotics,or vaccines during the month of 1 month.Stool samples from these children were collected,followed by viral particle enrichment and metagenomics sequencing analysis to classify and identify the gut DNA virome of the children and to understand the basic composition of the virome,as well as to perform viral gene function prediction and phage host prediction.All gut DNA virome in the samples were then studied primarily to compare the differences and similarities in the relative abundance of microorganisms at each level of viral classification between children with ASD and their healthy siblings,and to analyze the differences in gut viralα-diversity and β-diversity between the two groups of children.ResultsThe study participants were aged 3-11 years and were all Han Chinese.Data were obtained for a total of 23 samples of childhood gut virome.(1)Classification of the virome confirmed that the childhood gut DNA virome was predominantly phages(88.32%),with the Caudovirales Siphoviridae(78.55%)predominating.(2)The most dominant hosts predicted for phages were Streptococcaceae(20.14%),followed by Clostridiaceae(17.67%).(3)The most important genetic functions of gut virome are to carry out the processing of genetic information and metabolic functions.(4)Statistical analysis of DNA viral abundance showed a strong negative correlation between the Caudovirales and Petitvirales(r =-0.902).(5)The abundance of gut DNA virome between children with ASD and healthy siblings was not statistically different at the order level and family level,and a statistically significant difference was found for Skunavirus between the two groups at the genus level(Ζ=-2.157,P=0.031).(6)The clustering hierarchy of gut DNA virome between siblings in the same family was closer than those in different families and with a high similarity of community composition.(7)In the analysis of viral diversity between the two groups of children,α-diversity decreased in children with ASD but was not statistically different,and also β-diversity was not statistically different between the two groups of children.However,in the ASD group,there was a statistically significant difference in the α-diversity between children with and without gastrointestinal dysfunction(Ζ=-2.558,P=0.011).ConclusionThe enteric DNA virome of the children involved in this experiment were predominantly the Siphoviridae family of the Caudovirales.Compared with healthy siblings,the abundance of the intestinal DNA virome in children with autism was not significantly different at the order level and family level,and there were statistical differences in the abundance of the Skunavirus at the genus level.α-diversity of the virome was decreased,and there were no significant statistical differences between groups in α-diversity and β-diversity.It is suggested that the gut virome of children with autism has changed,which provides a preliminary experimental basis for a further large sample,microbial multi-omics experiments on virological aspects.